Control system for liquid dispensers

ABSTRACT

A control system for a liquid dispenser, such as a gasoline pump, the system being adapted to dispense a pre-set volume or dollar amount of gasoline. The control system includes a bank of normally open selector switches which are selectively closed by means of a manually adjustable knob whose setting determines the amount to be dispensed, and a like bank of detector switches which are selectively closed by means of a counter wheel which indicates the volume or the dollar amount of gasoline dispensed by the pump. Each pair of correspondingly numbered switches in the two banks is connected in series between a power source and a relay, whereby the relay is actuated only when a matching pair of switches are simultaneously closed. The relay, when actuated, acts to de-energize and brake the motor for the pump, whereby the flow of gasoline is immediately arrested when the amount dispensed is in accordance with the knob setting.

United States Patent [1 1 Pardee CONTROL SYSTEM FOR LIQUID DISPENSERS Munson H. Pardee, Clinton, NY.

[73] Assignee: Hamilton Digital Controls, Inc.,

Utica, NY.

Sept. 18, 1970 [75] Inventor:

[22] Filed:

' [21] Appl. No.: 73,384

[52] US. Cl. 222/20, 222/23 [51] Int. Cl B67d 5/30 [58] Field of Search 222/32, 33, 35, 59, 60,

[56] References Cited UNITED STATES PATENTS 9/1928 Pierce et al 222/32 X 4/1934 Smallhouse 1 222/496 X Aug. 20, 1974 Guttmann 194/13 Bly 194/13 5 7 ABSTRACT A control system for a liquid dispenser, such as a gasoline pump, the system being adapted to dispense a preset volume or dollar amount of gasoline. The control system includes a bank of normally open selector switches which are selectively closed by means of a manually adjustable knob whose setting determines the amount to be dispensed, and a like bank of detector switches which are selectively closed by means of a counter wheel which indicates the volume or the dollar amount of gasoline dispensed by the pump. Each pair of correspondingly numbered switches in the two banks is connected in series between a power source and a relay, whereby the relay is actuated only when a matching pair of switches are simultaneously closed. The relay, when actuated, acts to de-energize and brake the motor for the pump, whereby the flow of gasoline is immediately arrested when the amount dispensed is in accordance with the knob setting.

7 Claims, 4 Drawing Figures 1 CONTROL SYSTEM'FOR LIQUID DISPENSERS BACKGROUND OF THE INVENTION This invention relates generally to liquid dispensers such as gasoline pumps used to deliver gasoline at automobile service stations, and more particularly to an electronic control system operating in conjunction with a gasoline pump and adapted to dispense a predetermined volume or dollar amount of gasoline.

In modern gasoline pumps, flow is controlled by a valve in the nozzle on the end of a hose extending from the housing of the pump. The amount of gasoline dispensed and the cost thereof are indicated by accumulating counter wheels which are mounted on a display panel within the pump housing, the wheels being visible through a window. Two sets of counter wheels are provided, one for indicating the volume of gas dispensed in terms of gallons, and fractions thereof, the other in money amounts, i.e., in terms of dollars and cents. The two sets of wheels rotate about closely spaced parallel axes so that they are both visible to the operator and the customer in the same general area.

The manner in which the money counter wheels accumulate in relation to the gallon counter wheels is automatically adjustable in accordance with changes in the price of gasoline per gallon, for the price per gallon of regular gasoline is different from the price of premium or other grades thereof. Gasoline pumps of conventional design are arranged to automatically shut off the nozzle valve when the automobile tank to which gasoline is being delivered reaches the full state. However, if a customer wishes to buy less than a full tank, or a specified dollar amount of gasoline, the gas-station attendant must continue to observe the counters and maintain control over the nozzle valve in order to quickly close it when the desired amount of gasoline is indicated by the counters. This procedure is disadvantageous, for it is not only time-consuming but it is also subject to human error.

Various schemes have been proposed, making it possible for the operator of a gasoline pump to pre-set-the volume or money amount of gasoline to be dispensed, thereby obviating the need to maintain surveillance of the counters, as well as releasing the operator for other duties as gasoline is being metered into the customers tank.

Such schemes have had very limited commercial success, for the control systems involved were relatively complicated and costly, and generally entailed a substantial modification of the counter structure in the pump. Moreover, prior systems were neither reliable nor accurate, and were usually found unacceptable by various departments of weights and measures.

SUMMARY OF THE INVENTION In view of the foregoing, it is the primary object of this invention to provide a control system for a gasoline pump or other metered liquid dispenser which is adapted to dispense a predetermined volume or money amount of liquid.

Since approximately 85 percent of gasoline sales made in the United States are made in even dollar amounts ranging from 1 to 5 dollars, the invention will be described in an embodiment adapted to pre-set the pump to dispense fuel in even dollar amounts. Thus the customer need only indicate to the operator how many dollars worth of fuel he wishes to purchase. It will be appreciated, however, that the principles underlying the invention are also applicable to selling exact volume amounts, in which event the customer need only indicate how many gallons of gasoline he wishes to buy.

A significant advantage of the invention is that the system maintains accurate control over the gasoline dispenser, thereby avoiding an overrun which may give the customer a few cents more of gasoline than that to which he is entitled. While the overrun loss to the service station is generally very small per transaction, this loss may become substantial when the monthly transaction-losses are aggregated.

Another advantage of the invention is that the operator, once the pump is pre-set and started, may leave the pump unattended so that he is then free to perform other services as the automobile is being fueled. In installations having no attendants and in which the customer fuels his own tank, a system in accordance with the invention may be arranged to be coin-operated, so that the setting is determined by how many coins are deposited.

Also an object of the invention is to provide a control system of the above type which is simple and yet efficient and reliable in operation, and which can be manufactured inexpensively and readily installed in an existing pump having counters.

Briefly stated, these objects are attained in a control system for a motor-operated fuel pump having a hose terminating in a nozzle, gasoline being delivered to the nozzle when the motor is energized. The gasoline pump includes counter wheels for indicating the volume and money amount of gasoline being dispensed. The control system comprises a bank of normally open selector switches which are selectively closed by means of a manual control knob whose setting determines the amount to be dispensed, and a like bank of detector switches which are selectively closed by means of a counter wheel which indicates the volume or dollar amount.

Each pair of correspondingly numbered switches in the two banks is connected in series between a power source and a relay, whereby the relay is actuated only when a matching set of switches are simultaneously closed..When actuated, the relay functions to cut off and brake the pump motor, whereby the flow of gasoline is immediately arrested when the amount dispensed conforms to the knob setting in terms of dollars or gallons.

' OUTLINE OF THE DRAWING For a better understanding of the invention, as well as other objects and further features thereof, reference is made to the following detailed description to be read in conjunction with the accompanying drawing wherein:

FIG. 1 illustrates a gasoline pump having installed therein a preferred embodiment of a control system in accordance with the invention;

FIG. 2 is a schematic electrical diagram of the control system;

FIG. 3 is an exploded view of the control knob and selector-switch assembly; and

FIG. 4 is an exploded view of the dollar-digit wheel and detector-switch assembly.

DESCRIPTION OF THE INVENTION Referring now to FlG. 1, there is shown a typical gasoline pump, generally designated by numeral 10, and

including an upright housing 11 mounted upon an is land 12 located at an automobile service station. Extending from one side of the housing is a flexible hose 13 which terminates in a nozzle 14. Nozzle 14 is provided with a handle 15 to enable an operator to insert it into the gas tank of an automobile 16 parked adjacent the island.

Within the handle of the nozzle is a lever 17 which, when raised by the operator, opens a normally-closed main valve in the nozzle to permit gasoline to flow from the hose into the tank. The nozzle is preferably of the type disclosed in U.S. Pat. No. 2,582,195, wherein the nozzle also includes a spring-biased check valve which is pressure-responsive and closes automatically when there is a drop .in fuel pressure in the hose. Consequently, when the pump motor which feeds gasoline switches in banks 22 and 23 are simultaneously closed.

into the hose is de-energized by the control system, the

resultant drop in pressure causes the check valve to shut, thereby preventing the hose from draining. This leaves a full hose at all times.

Pump housing 11 contains accumulative-type counter wheels which are caused to rotate as gasoline is pumped from a storage tank into the upper end of the hose through a flowmeter. The flowmeter measurement is conveyed to the counter wheels, which rotate and thereby accumulate the amount of gasoline dispensed from the nozzle. This amount is indicated in both money and volume amounts. The money amount in dollars and cents is shown by the upper set of wheels 18, and the volume in gallons and fractions thereof is shown by the lower and parallel set of wheels 19. The wheels are mounted on a display panel disposed behind a window so that they are clearly visible to the operator and to the customer.

Mounted on the other side of the pump housing 11 is a dollar selector panel 20 having a knob 21 which is adjustable to l, 2, 3, 4 and S-dollar amounts. In the event the system is set up to deliver even gallon amounts, the knob settings will be a series of gallon numbers. While a greater number of setting positions may be used, it is rare under present gasoline price levels in the United States to receive customer requests exceeding 5 dollars.

When knob 21 is set to a specified amount, the nozzle will dispense gasoline until this amount is reached, at which point the pump motor is cut ofi and braked. The resultant loss of pressure in the hose causes the pressureresponsive check valve in the nozzle to close, thereby preventing the hose from draining. Thus the control system manipulates the existing pump motor and has no direct control over valves in the fluid lines.

Obviously in the case of D-C operated motors, the source is direct current, and in the case of A-C operated motors, the source is alternating.

' The arrangement is such that when control knob 21 is adjusted to close, say, switch 3 in selector bank 22, relay 25 will be actuated only when the dollar digitwheel closes switch 3 in detector bank 23. Similarly, relay 25 will be actuated when knob 21 closes switch 5 of bank 22, and wheel 24 closes switch 5 of bank 23. Thus relay 25 is actuated only when the dollar wheel reaches the selected dollar value.

While relay 25 is shown as an electromagnetic de vice, it will be appreciated that in practice one may use electronic relays, such as SCR devices. Also, one may encapsulate the various electronic components in a fire-retardant epoxy material to render the system ex plosion-proof.

Y Relay 25 is operatively associated with an armature 25A which normally engages a fixed contact I, but, when actuated, engages a fixed contact ll. Thus the armature and its contacts act as a single-pole, doublethrow switch. When contact I is engaged, power from a source is applied through an on-otf power switch 26 to the field winding of pump motor 27 to cause fuel to be pumped into the hose. But when the pre-set dollar amount is reached by dollar wheel 24 and relay 25 pulls the armature to contact II, then power to the motor is interrupted and momentarily applied through capacitor 28 to winding 29 of an electromagnetic brake for a time-constant period determined by resistor 30.

Thus when the pre-set dollar amount is reached by the pump counter, the pump motor is automatically cut off and braked to immediately arrest the flow of gasoline, so that the amount of gasoline dispensed does not exceed the pre-set dollar value, thereby obviating an overrun.

The manner in which control knob 21 acts to actuate switches 1 to 5 in selector-switch bank 22, is shown in FIG. 3, where it will be seen that the switches which, in practice, are magnetically actuated reed switches, are arranged within radially displaced slots on a stationary disc 31. Associated with stationary disc 31 is a rotatable selector disc 32 which is operatively coupled to and turned by knob 21.

Selector disc 32 incorporates a small permanent magnet 33 which in practice may be made of Alnico or other suitable material. The periphery of disc 32 has spaced notches 32 to 32 formed therein which cooperate with a detent 34, whereby magnet 33 may be selectively brought into registration with any one of switches l to 5 in the selector-switch bank 22 on stationary disc 31, to cause the selected switch to close. Thus by turning knob 21 to any one of five angular positions, the related switch is closed. Knob 21 is associated with a dial having indicia in volume or dollar amounts.

The manner in which the dollar digit-wheel 24 actuates a selected switch in the detector-switch bank 23 is shown in FIG. 4. it will be seen that embedded in dollar digit-wheel 24 is a small permanent magnet 35 whose radial position is aligned with the zero mark on the wheel.

Associated with rotatable dollar-wheel 24 is a stationary disc 36 having embedded therein in radially displaced slots, the switches 1 to 5 of the detector-switch bank. These switches are magnetically-actuated reed switches, and are so placed that when dollar-wheel 24 indicates 1 dollar, switch 1 is closed; when it indicates 2 dollars, switch 2 is closed, and so on. Thus when the dollar counter wheel reaches an even value which matches the pre-set value, the appropriate switches in both banks are closed to shut off and brake the motor.

In lieu of a control knob, one may provide a coinoperated device which is adapted to effect rotation of selector disc 32 in accordance with the number of coins deposited, so that when, say, 2 dollars in coins are deposited, the number 2 switch in the selector bank is closed to cause the system to shut off after 2 dollars worth of gasoline has been dispensed. This arrangement makes possible unattended operation of a pump, and yet provides a high measure of security.

While there has been shown and described a preferred embodiment of control system for fluiddispensing pumps in accordance with the invention, it will be appreciated that many changes and modifications may be made therein without departing from the essential spirit of the invention.

1 claim:

1. A control system for a fluid-dispensing pump having a motor to operate the pump and a counter wheel indicating the exact money or volume amount of fluid being dispensed, said pump being coupled by a hose to a nozzle having a pressure-responsive check valve whereby when the motor is deenergized, the resultant drop in fluid pressure effects closure of the check valve to prevent the hose from draining, said system comprismg:

7 A. a selector-switch bank constituted by a series of normally open, magnetically-actuated switches,

B. a detector-switch bank constituted by a like series of normally open, magnetically actuated switches, the switches in said bank being disposed at radially displaced positions in the proximity of said wheel,

C. means connecting each pair of correspondinglynumbered switches in the two banks in series between a power source and a relay whereby the relay is actuated only when any matching pair of switches are closed,

D. means including a master switch for connecting said power source to said motor to energize said motor, thereby operating said pump,

E. control means selectively to place a first permanent magnet in the proximity of any switch in the selector bank to effect closure thereof,

F. a second permanent magnet borne by said counter wheel at a position therein at which, when the wheel is oriented to indicate an exact amount, closure of a related switch in the detector bank is effected, and

G. means responsive to the actuation of said relay to first interrupt the connection between said power source and said motor to de-energize said motor and to immediately thereafter apply a braking force to the motor thereby effecting closure of said valve to abruptly arrest the flow of liquid whereby the amount of fluid dispensed does not exceed the amount set by said control means.

2. A system as set forth in claim 1, wherein said switches in said banks are reed switches.

3. A system as set forth in claim 1, wherein said means responsive to the actuation of said relay is a single-pole, double-throw switch which in its normal position applies power to said motor, and in its actuated position switches said power to an electromagnetic brake for the motor.

4. A system as set forth in claim 1, wherein said first permanent magnet is embedded in a rotatable selector disc which is coupled to and turned by a knob, said rotatable disc being coaxial with and adjacent to a stationary disc having the switches of the selector bank embedded therein at radially displaced positions.

5. A system as set forth in claim 4, further including a detent associated with said rotatable disc to maintain said disc at a series of selected positions.

6. A system as set forth in claim 1, wherein said control means is manually operated.

7. A control system for a fluid-dispensing pump having a motor to operate the pump and a counter wheel indicating the exact money or volume amount of fluid being dispensed, said pump being coupled by a hose to a nozzle having a pressure-responsive check valve whereby when the motor is de-energized, the resultant drop in fluid pressure effects closure of the check valve to prevent the hose from draining, said system comprismg:

A. a selector-switch bank constituted by a series of V normally open switches,

B. a detector-switch bank constituted by a like series of normally open switches,

C. means connecting each pair of correspondingly numbered switches in the two banks in series between a power source and a relay whereby the relay is actuated only when any matching pair of switches are closed,

D. means including a master switch to connect said power source to said motor to energize said motor, thereby operating said pump,

E. control means selectively to effect closure of any switch in the selector bank,

F. means coupling said counter wheel to said detector bank such that when said wheel is oriented to indicate an exact amount, closure of a related switch in the detector bank is effected, and

G. means responsive to the actuation of said relay to first interrupt the connection between said power source and said motor to de-energize said motor and to immediately thereafter apply a braking force to the motor, thereby effecting closure of said valve to abruptly arrest the flow of liquid whereby the amount of fluid dispensed does not exceed the amount set by said control means. 

1. A control system for a fluid-dispensing pump having a motor to operate the pump and a counter wheel indicating the exact money or volume amount of fluid being dispensed, said pump being coupled by a hose to a nozzle having a pressure-responsive check valve whereby when the motor is deenergized, the resultant drop in fluid pressure effects closure of the check valve to prevent the hose from draining, said system comprising: A. a selector-switch bank constituted by a series of normally open, magnetically-actuated switches, B. a detector-switch bank constituted by a like series of normally open, magnetically actuated switches, the switches in said bank being disposed at radially displaced positions in the proximity of said wheel, C. means connecting each pair of correspondingly-numbered switches in the two banks in series between a power source and a relay whereby the relay is actuated only when any matching pair of switches are closed, D. means including a master switch for connecting said power source to said motor to energize said motor, thereby operating said pump, E. control means selectively to place a first permanent magnet in the proximity of any switch in the selector bank to effect closure thereof, F. a second permanent magnet borne by said counter wheel at a position therein at which, when the wheel is oriented to indicate an exact amount, closure of a related switch in the detector bank is effected, and G. means responsive to the actuation of said relay to first interrupt the connection between said power source and said motor to de-energize said motor and to immediately thereafter apply a braking force to the motor thereby effecting closure of said valve to abruptly arrest the flow of liquid whereby the amount of fluid dispensed does not exceed the amount set by said control means.
 2. A system as set forth in claim 1, wherein said switches in said banks are reed switches.
 3. A system as set forth in claim 1, wherein said means responsive to the actuation of said relay is a single-pole, double-throw switch which in its normal position applies power to said motor, and in its actuated position switches said power to an electromagnetic brake for the motor.
 4. A system as set forth in claim 1, wherein said first permanent magnet is embedded in a rotatable selector disc which is coupled to and turned by a knob, said rotatable disc being coaxial with and adjacent to a stationary disc having the switches of the selector bank embedded therein at radially displaced positions.
 5. A system as set forth in claim 4, further including a detent associated with said rotatable disc to maintain said disc at a series of selected positions.
 6. A system as set forth in claim 1, wherein said control means is manually operated.
 7. A control system for a fluid-dispensing pump having a motor to operate the pump and a counter wheel indicating the exact money or volume amount of fluid being dispensed, said pump being coupled by a hose to a nozzle having a pressure-responsive check valve whereby when the motor is de-energized, the resultant drop in fluid pressure effects closure of the check valve to prevent the hose from draining, said system comprising: A. a selector-switch bank constituted by a series of normally open switches, B. a detector-switch bank constituted by a like series of normally open switches, C. means connecting each pair of correspondingly numbered switches in the two banks in series between a power source and a relay whereby the relay is actuated only when any matching pair of switches are closed, D. means including a master switch to connect said power source to said motor to energize said motor, thereby operating said pump, E. control means selectively to effect closure of any switch in the selector bank, F. means coupling said counter wheel to said detector bank such that when said wheel is oriented to indicate an exact amount, closure of a related switch in the detector bank is effected, and G. means responsive to the actuation of said relay to first interrupt the connection between said power source and said motor to de-energize said motor and to immediately thereafter apply a braking force to the motor, thereby effecting closure of said valve to abruptly arrest the flow of liquid whereby the amount of fluid dispensed does not exceed the amount set by said control means. 